Treesearch

The linkages among forests, water, and people have long been recognized by natural resources professionals and policymakers. This report, in support of the U.S. Department of Agriculture, Forest Service, Southern Research Station’s Southern Forest Outlook, provides a contemporary assessment of current and future forest and water resource issues in the Southern United States, a region encompassing the 13 Southern States from Virginia to Texas. This report uses a combination of literature review, hydrologic modeling, and data synthesis to address pressing research questions, leveraging...

Ecocultural restoration involves the reciprocal repair of ecosystems and revitalization of cultural practices to enhance their mutual resilience to natural and anthropogenic disturbances and climate change stressors. Resilient ecocultural systems are adapted to retain structure and function in the face of disturbances that remain within historical ranges of severity. To assist in ecocultural restoration and management, understanding how a system has historically responded to different types of disturbances is therefore invaluable in understanding how social-ecological resilience can be...

Coastal giant salamanders (Dicamptodon tenebrosus) have lived in forests of the Pacific Northwest for tens of thousands of years. Their survivability is a testament to their ability to withstand and adapt to long-term changes. But can they withstand a succession of more rapid changes resulting from human intrusion and compounded by climate change? Dede Olson, a scientist with the USDA Forest Service Pacific Northwest Research Station, has studied the intersection of salamanders and forest management practices for more than 30 years. She recently conducted studies of how the management of...

Non-native ungulates (sheep, goats, and pigs) have significant negative impacts on ecosystem biodiversity, structure, and biogeochemical function throughout the Pacific Islands. Elevated nitrogen (N) availability associated with ungulate disturbance has been shown to promote the success of resource-exploitive invasive plants. While ungulate removal is a common restoration intervention, evaluations of its efficacy typically focus on vegetation responses, rather than underlying nutrient cycling. We used multiple chronosequences of ungulate exclusion (10–24 years duration) in three Hawaiian...

Past research on barriers to the development and implementation of green infrastructure (GI) has examined the experiences of policy makers and community leaders, with a focus on planting or installing GI. However, many of these programs rely on participation from the public — especially residents — who often steward GI over the long-term on both public and private lands. To better understand the barriers experienced by primary stewards of GI, we conducted 93 intercept interviews with residents spanning four neighborhoods in the City of Philadelphia and in four nearby suburban municipalities...

Street trees are highly visible components of the urban forest, providing ecosystem services to city residents, but tree mortality can result in a loss of these essential benefits. Here, we focus on how street tree survival in Philadelphia, Pennsylvania (US) has been influenced by 1) tree traits and attributes, 2) the local biophysical environment, and 3) socioeconomic context. We used a longitudinal monitoring approach with a 6-year time interval and 103 randomly-located, fixed-length permanent plots, containing a range of tree size classes, to assess street tree survival rates, predictors...

Large forest fires have far-reaching impacts on the environment, human health, infrastructure and the economy. Forest fires become large when all forest types across a landscape are dry enough to burn. Mesic forests are the slowest to dry and can act as a barrier to fire growth when they are too wet to burn. Therefore, identifying the factors influencing fire occurrence in mesic forests is important for gauging fire risk across large landscapes. We quantified the key factors influencing the likelihood that an active wildfire would propagate through mesic forest. We analysed 35 large forest...

Fire suppression is the primary management response to wildfires in many areas globally. By removing less-extreme wildfires, this approach ensures that remaining wildfires burn under more extreme conditions. Here, we term this the “suppression bias” and use a simulation model to highlight how this bias fundamentally impacts wildfire activity, independent of fuel accumulation and climate change. We illustrate how attempting to suppress all wildfires necessarily means that fires will burn with more severe and less diverse ecological impacts, with burned area increasing at faster rates than...

The Mississippi Embayment (ME) is one of the fastest groundwater depletion zones in the world. This study investigated stream-aquifer water exchange in the ME over a 115-year period (1900 to 2014) under normal and extreme climates (i.e., precipita-tion increased and decreased by 20%) with and without agricultural pumping for crop irrigation. The average daily water flow from the aquifer to the streams was always greater than vice versa under all climate scenarios. Under normal climate, the aver-age daily water flow from the aquifer to the streams was 2.52 times larger without pumping than...

Many agricultural production regions in the world have been experiencing groundwater resource depletion, which threatens water and food security if mitigation practices are not developed and implemented. To understand how changing land use and irrigation schedule impact groundwater, a coupled SWAT-MODFLOW model was applied to determine groundwater depletion mitigation strategy in a humid region, the Big Sunflower River Watershed (BSRW) in Mississippi, USA. It was found that converting grasslands to forests contributed to reducing groundwater declining. Simulated results indicated that the...